KR20060082509A - Multi-tip probe and method of manufacturing the same - Google Patents

Abstract

Multi-tip probes and methods of making the same are disclosed. Disclosed is a multi-tip probe comprising a support, a cantilever having one end connected to the support, and at least two tips formed on the other end of the cantilever, wherein the cantilever is spaced at a given interval and is independent of the first and second cantilevers. It provides a multi-tip probe and its manufacturing method comprising a.

Description

Multi-tip probe and method of manufacturing the same

1 is a cross-sectional view of a multi-tip probe according to the prior art.

2 is a bottom view of FIG. 1.

3 is a cross-sectional view of a multi-tip probe according to an embodiment of the present invention.

4 is a bottom view of FIG. 3.

5 and 8 are bottom views showing step by step a method of manufacturing a multi-tip probe according to an embodiment of the present invention.

FIG. 6 is a cross-sectional view of a portion of the figure shown in the circle of FIG. 5 cut in the 6-6 direction.

FIG. 7 is a cross-sectional view of a portion of the original view of FIG. 5 taken in the 7-7 direction. FIG.

* Description of the symbols for the main parts of the drawings *

40: support body 42, 50: cantilever

42a, 50a: first cantilever 42b, 50b: second cantilever

44, 60: tip 44a, 60a: first tip

44b, 60b: second tip 46a, 46b: first and second wirings

D, D3: first and second cantilever (tip) spacing D1: width of the upper flat portion of the tip matrix

h: hall

The present invention relates to a measuring device, and more particularly, to a multi-probe for Spreading Resistance Analysis (SRA).

Most semiconductor devices, as well as memory devices such as DRAM, FLASH, and FRAM, include MOSFETs (Metal Oxide Silicon Field Effect Transistors). In the MOSFET, the source and drain regions are formed by ion implanting impurities such as boron (B), phosphorus (P), or arsenic (As) into a limited region of the semiconductor substrate on a P-type or N-type semiconductor substrate. Impurity concentration distribution in the source and drain regions is an important design variable in the fabrication of semiconductor devices. Therefore, it is necessary to measure the impurity concentration in the process of manufacturing the actual semiconductor device for the design of the semiconductor device.

In the process of manufacturing a semiconductor device, a method of determining the impurity concentration or impurity profile of a selected region of a semiconductor substrate, such as secondary ion mass spectroscope (SIMS), chemical etching decoration (CED), and scanning spreading resistance microscope (SSRM) ) Or SCM (Scanning Capacitance Microscope) has been studied.

SIMS, a kind of failure test, has been added recently to add a two-dimensional display mode called mapping, but it is sufficient to measure the source-drain region because the concentration of ions is generally micron order. Cannot have resolution.

The method using SCM, a technique using Scanning Probe Microscope (SPM), has a better horizontal resolution than the method using SIMS, but it is difficult to quantify the injected impurities because it is difficult to obtain depth information and measures the spatial variation of capacitance. There are disadvantages.

In order to complement the method using the SIMS and the method using the SCM, a method of etching with an etching solution having a different etching rate according to the impurity concentration and inducing the impurity concentration profile from the shape of the etching result has been introduced. See USP 6,121,060). However, this method has a disadvantage in that the analysis method is complicated to perform because the impurity concentration is determined indirectly as a kind of destruction test like the SIMS method.

Recently, an analysis method using Scanning Spreading Resistance Microscope (SSRM) combining a method using a Spreading Resistance Profiler (SRP) and a method using a Scanning Probe Microscope (SPM) has contacted a sample with a conductive probe used in the SPM method. Applying a constant voltage to measure the amount of current flowing into the sample from the conductive probe to determine the change in the impurity concentration of the sample. In this method, since the change in the concentration of impurities can be known from the change in current, the discrimination power of concentration is high.

Various probes are used in the above-described analysis method. For example, in the case of an analysis method using SRP, a probe in which a multi-tip 10 is formed at the end of a cantilever 12 is used as shown in FIG. 1. In FIG. 1, reference numeral 16 is a support of the cantilever 12.

Referring to FIG. 2, which is a bottom view of FIG. 1, it can be seen that the multi-tip 10 is composed of spaced apart first and second tips 10a and 10b. In FIG. 2, reference numerals 18a and 18b denote first and second wires connected to the first and second tips 10a and 10b through the cantilever 12, respectively.

The distance between the first and second tips 10a and 10b of the probes shown in FIGS. 1 and 2 (hereinafter, referred to as conventional probes) is several micrometers or more. impossible. In addition, the first and second tips 10a and 10b of the conventional probe are integrated in one cantilever 12, and the space to be integrated is also narrow. Therefore, the design of the tip 10 is difficult and not easy to manufacture. In addition, since it is difficult to form the first and second tips 10a and 10b at exactly the same height due to a process error, it is difficult to bring both the first and second tips 10a and 10b into contact with the measurement object. For this reason, it is difficult to obtain a three-dimensional profile for the measurement object using a conventional probe.

The technical problem to be achieved by the present invention is to improve the above problems of the prior art, it is possible to analyze the measurement target having a nano-size, Spreading Resistance Analysis (SRA) to obtain a three-dimensional profile of the measurement target It is to provide a multi-tip probe () for).                         

Another object of the present invention is to provide a method for manufacturing the multi-tip probe.

In order to achieve the above technical problem, the present invention is a multi-tip probe comprising a support and a cantilever, one end connected to the support and at least two tips formed on the other end of the cantilever, wherein the cantilever is spaced at given intervals and is independent It provides a multi-tip probe, characterized in that it comprises a first and a second cantilever.

Each other end of the first and second cantilevers may be spaced apart by several tens of nanometers.

First and second tips may be provided at the other ends of the first and second cantilevers, respectively, and the first and second tips may have the same height, and may be spaced apart from each other at the same interval as the first and second cantilevers. .

Sensors capable of sensing the warpage of the first and second cantilevers may be attached to the first and second cantilevers, respectively.

In order to achieve the above another technical problem, the present invention provides a support, a cantilever one end connected to the support, and at least two tips formed on the other end of the cantilever, the size of the other end of the cantilever A first step of forming a tip matrix larger than the sum of the at least two tips and a second step of dividing the cantilever and the tip matrix to be symmetrical. do.

In the manufacturing method as described above, the second step may simultaneously divide the cantilever and the tip matrix by using a focused ion beam.

The tip matrix may be at least several tens of nanometers larger than the sum of the at least two tips.

Two sensors may be formed in the cantilever so as to be provided in each of the two cantilevers obtained after the second step.

Using the present invention, since the bisected cantilevers can move independently of each other and have elasticity, the tips formed at the ends of the cantilevers can move in accordance with the surface curvature of the object to be measured. By detecting the tip movement, it is possible to know the surface curvature of the measurement target. The three-dimensional shape of the surface to be measured is known. In addition, since the interval between the multi-tips of the present invention is as narrow as 50 nm, it is possible to analyze the measurement target having a much smaller size than the conventional one. In other words, the resolution of analysis can be increased much. Therefore, when the probe of the present invention is applied to a probe card used to check whether there is an abnormality in the manufacturing process of a semiconductor device, a probe card that can be used to confirm an abnormality of a manufacturing process of a semiconductor device having a higher degree of integration. (Hereinafter referred to as a probe card for a highly integrated semiconductor device) can be implemented.

Hereinafter, a multi-tip probe (probe of the present invention) and a method of manufacturing the same according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this process, the thicknesses of layers or regions illustrated in the drawings are exaggerated for clarity.

First, the probe of this invention is demonstrated.

Referring to FIG. 3, a cantilever 42 of a predetermined length is connected to one side of the bottom surface of the support 40. A tip 44 is formed at the end of the cantilever 42. The tip 44 is formed in the opposite direction to the support 40. The support 40, the cantilever 42, and the tip 44 may be formed of a predetermined semiconductor, for example, silicon (Si). The tip 44 is slightly inward from the end of the cantilever 42 as shown in the first circle C1a, which shows an enlarged view of a predetermined area C1 of the probe including the tip 44 and a portion of the cantilever 42. It may be provided in, but may be provided at the end of the cantilever 42, as shown in the second circle (C1b).

Referring to FIG. 4, which shows the bottom of FIG. 3, there are first and second wirings 46a and 46b spaced apart from the bottom of the support 40. The first and second wirings 46a and 46b may be metal wirings or doped regions into which conductive impurities are injected. The cantilever 42 is composed of first and second cantilevers 42a and 42b. One end of the first cantilever 42a is connected to the first wiring 46a. One end of the second cantilever 42b is connected to the second wiring 46b regardless of the first cantilever 42a. The other end, that is, the end of the first and second cantilevers 46a and 46b is spaced apart by a predetermined interval D, and the interval D may be about 50 nm or more. The spacing D may be narrower or wider than 50 nm depending on the resolution of the focused ion beam irradiation apparatus used to form the first and second cantilevers 46a and 46b. The first and second cantilevers 42a and 42b have elasticity. As a result, the first and second cantilevers 42a and 42b may be bent to some extent in the vertical direction, and may immediately return to their original positions after being bent. Tip 44 is a multi-tip comprising a first tip 44a and a second tip 44b. As shown in (b) and (c) of FIG. 4, which enlarge the predetermined region P1 of the probe, the first and second tips 44a and 44b are respectively the first and second cantilevers 42a. , 42b) may be formed slightly inward, or may be formed at the ends of the first and second cantilevers 42a and 42b. For the latter, the ends of the first and second cantilevers 42a, 42b may be machined to coincide with the ends of the first and second tips 44a, 44b during probe fabrication. The first and second tips 44a and 44b are provided at positions facing each other in front. In addition, the first and second tips 44a and 44b are spaced at the same interval D as the first and second cantilevers 42a and 42b. Thus, when the first and second cantilevers 42a and 42b are in contact, the first and second tips 44a and 44b are also correctly contacted.

Next, a method of manufacturing the probe of the present invention described above will be described.

Referring to FIG. 5, the tip matrix 60 is formed slightly inward from the ends of the first and second wirings 46a and 46b, the cantilever monolith 50 connected to one end of the support 40, and the cantilever monolith 50. Until the normal process is followed. However, a triangular hole h is formed in the inner portion of the cantilever unit 50. The triangle-shaped hole h is formed so that the bottom side becomes the boundary of the support body 40 and the cantilever unit 50. In addition, the tip matrix 60 is formed so that the cross section cut in the 6-6 direction has a rhombus shape as shown in FIG. 6, and the cross section cut in the 7-7 direction is formed as a triangle as shown in FIG. At this time, the width D1 of the upper parallel portion 60a in FIG. 6 is preferably formed in consideration of the resolution of the dividing means used for dividing the tip parent 60 and the cantilever monolith 50 in a subsequent process. For example, when the resolution of the dividing means is about 50 nm, the tip matrix 60 is formed so that the width D1 of the parallel portion 60a is about 50 nm, and when the resolution of the dividing means is higher, the tip matrix ( 60 may be formed such that the width D1 of the parallel portion 60a is narrower than 50 nm.

Subsequently, after the cantilever monolith 50 and the tip matrix 60 are formed to satisfy the above conditions, the dividing process of dividing the tip matrix 60 of the cantilever monolith 50 into two is performed.

In FIG. 5, the diagram in circle C2 is an enlarged view of a partial region P2 including the tip matrix 60 of the cantilever monolith 50, which the bifurcation process refers to.

Specifically, in the dividing process, a part of the cantilever monolith 50 and the tip parent 60 belonging to the inside of the first and second dotted lines L1 and L2 are removed using predetermined dividing means. The interval between the first and second dotted lines L1 and L2 is equal to the width D1 of the upper parallel portion 60a of the cantilever monolith 50 shown in FIG. 6. Therefore, the interval between the first and second dotted lines L1 and L2 may vary depending on the resolution of the predetermined dividing means. The dividing means may be, for example, a focused ion beam irradiation apparatus. The dividing process can proceed from the hole h to the end of the cantilever monolith 50 or vice versa. When the dividing means is a focused ion beam irradiation apparatus, the user can accurately adjust the spot size of the ion beam from several nanometers or tens of nanometers to several micrometers according to the resolution thereof. Therefore, the cantilever monolith 50 and the tip parent 60 can be precisely divided using the dividing means, so that the result obtained after the dividing process is exactly symmetrical.

8 shows the result of performing the dividing process using the dividing means. 5 and 8, it can be seen that the cantilever monolith 50 of FIG. 5 is divided into first and second cantilevers 50a and 50b which are exactly symmetrical, and the tip parent 60 is also exactly symmetrical. It can be seen that the bifurcated into the first and second tips 60a, 60b. The first and second cantilevers 50a and 50b are the same as the first and second cantilevers 42a and 42b of FIG. 4, respectively, and the first and second tips 60a and 60b are the first and second cantilevers 50a and 60b respectively. It is the same as the second tips 44a and 44b. In addition, the spacing D3 between the first and second tips 60a and 60b of FIG. 8 may be equal to or different from the spacing D between the first and second tips 44a and 44b.

On the other hand, although not shown in the drawings, the first and second cantilever can be attached to each of the sensors that can detect the warp of the first and second cantilever can measure the degree of warpage of the cantilever every moment. Through this measurement, it is possible to obtain information on the surface shape of the measurement target that the tip is in contact with, and by analyzing such information, two-dimensional and three-dimensional profiles of the surface shape of the measurement target may be obtained.

While many details are set forth in the foregoing description, they should be construed as illustrative of preferred embodiments, rather than to limit the scope of the invention. For example, one of ordinary skill in the art may modify the tip of the cantilever, and the technical idea of the present invention may be applied to a probe used for measuring physical quantities other than SRA measurement. In addition, when the wiring is formed by the doping method, the conductive impurity may be doped on the entire back surface of the cantilever and the support. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined by the technical spirit described in the claims.

As described above, in the probe of the present invention, since each of the two cantilevers is elastic, the tip formed at the end of the cantilever may move in accordance with the surface curvature of the object to be measured. By sensing the movement of the tip, it is possible to know the surface curvature of the object to be measured. In addition, since the interval between the multi-tips of the present invention is as narrow as about 50 nm, it is also possible to analyze the measurement target having a much smaller size than the conventional one. In other words, the resolution of analysis can be increased much. Furthermore, the present invention can also be applied to probe cards for high integrated semiconductor devices.

Claims (8)

In the multi-tip probe comprising a support, a cantilever one end connected to the support, and at least two tips formed on the other end of the cantilever, And the cantilever includes independent first and second cantilevers spaced at given intervals. The multi-tip probe of claim 1, wherein the other ends of the first and second cantilevers are spaced apart by several tens of nanometers. 2. The apparatus of claim 1, wherein first and second tips are provided at the other ends of the first and second cantilevers, respectively, and the first and second tips have the same height and have the same spacing as the first and second cantilevers. Multi-tip probes, characterized in that spaced apart. The multi-tip probe according to claim 1, wherein a sensor capable of detecting a warpage of the first and second cantilevers is attached to the first and second cantilevers, respectively. In the manufacturing method of the multi-tip probe having a support, a cantilever one end connected to the support, and at least two tips formed on the other end of the cantilever, A first step of forming a tip matrix at the other end of the cantilever, the size of which is larger than the sum of the at least two tips; And And dividing the cantilever and the tip matrix into symmetry. 6. The method of claim 5, wherein the second step comprises simultaneously dividing the cantilever and the tip matrix using a focused ion beam irradiation apparatus. 6. The method of claim 5 wherein the tip matrix forms at least several tens of nanometers greater than the sum of the at least two tips. 6. The method of claim 5, wherein two cantilevers obtained after the second step are respectively provided on the cantilever to form two sensors capable of detecting the warp of the cantilever.

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